Background: Minimally invasive techniques are being used increasingly in patients with benign and malignant breast diseases. The purpose of this study was to compare the diagnostic yield of 2 groups of patients who underwent either minimally invasive microductectomy or major duct excision for pathologic nipple discharge.
Methods: Two hundred thirty-five patients who underwent nipple exploration and duct excision and were part of an institutional review board-approved database were included in this retrospective analysis. Preoperative imaging, ductal washing cytology, surgical specimen size, and final histopathology were compared among 95 patients who underwent microductectomy by using intraoperative ductoscopy and 140 patients undergoing standard major duct excision.
Results: Mean age of patients undergoing microductectomy was 53 versus 55 years in patients undergoing major duct excision. Preoperative mammogram was negative or benign in 92% and suspicious in 8% of patients in both the microductectomy group and the major duct excision group. A ductal abnormality was identified by preoperative ductography in 43 of 56 (77%) patients in the microductectomy group versus 74 of 92 (80%) patients in the major duct excision group. Ductal cytology was benign in 81% and 80% of patients tested, respectively. Mean specimen size was significantly smaller in patients who underwent microductectomy (9.2 cm3) as compared with major duct excision (12.6 cm3). Although the percentage of patients with atypical ductal hyperplasia or lobular carcinoma in situ was similar among the 2 groups (9% vs 10%), only 3 of 95 (3%) patients within the microductectomy group were found to have carcinoma within the resection specimen as compared with 12 of 140 (9%) within the major duct excision group (P = .03). Mean specimen size of the patients diagnosed with carcinoma was 8.6 cm(3) in the microductectomy group as compared with 15.5 cm3 in the major duct excision group (P = .014).
Conclusions: These data confirm that patients who present with single duct pathologic nipple discharge usually have benign pathology as the etiology. However, in a small percentage of patients an occult carcinoma might be present. Major duct excision appears to detect a higher percentage of occult carcinoma when compared with minimally invasive microductectomy, which might be related to the larger sample size of the resection specimen.